The present invention relates to spinous process distraction and, in particular, it concerns a device and method for minimally invasive deployment to achieve spinous process distraction.
Various devices have been proposed for distraction between adjacent spinous processes, or more precisely, to prevent extension at one or more level between adjacent vertebrae in order to treat various spinal conditions. Examples of such devices are described in U.S. Pat. Nos. 6,152,926, 6,695,842, US2004/0153071 and WO03007791 which may be referred to for further background to the physiological aspects of the present invention.
Although the above documents refer to minimally invasive techniques for implanting the devices disclosed, the deployment of the element in a latero-lateral direction via a dorsal-angled approach is non-trivial, requiring sizable incisions and manipulation within the body to achieve the required deployment of an implant. In some cases, spinous process distraction devices necessitate bilateral access during implantation, thereby necessarily increasing trauma from the procedure compared to a unilateral approach. On the other hand, attempts to implement a unilateral approach device would present more complex obstacles regarding the correct latero-lateral alignment of the device.
PCT patent application publication no. WO 2006/072941 teaches a wide range of devices and corresponding applications in which an elongated element is introduce into a body in a straightened configuration and then assumes a curved or coiled configuration within the body. The aforementioned publication is hereby incorporated by reference herein in its entirety.
It would therefore be highly advantageous to provide a method and device according to the principles of the aforementioned WO 2006/072941 which would employ the deflectable structure to facilitate correct placement of an inter spinous process implant from a unilateral dorsal-angled approach.